Arthritis of the knee joint is one of the most common causes of knee pain. There are different types of arthritis that can affect the knee joint, and the treatments may vary depending on the condition that is causing the symptoms.
Osteoarthritis is the most common type of knee arthritis. Also called wear-and-tear arthritis or degenerative joint disease, osteoarthritis is characterized by progressive wearing away of the cartilage in the joint. As the protective cartilage is worn away, bone is exposed, the knee becomes swollen and painful, and activities become increasingly painful.
Knee arthritis typically affects patients as they get older. Symptoms are more common in patients who are overweight, and weight loss tends to reduce the severity of pain associated with knee arthritis. There is also a genetic component, meaning knee arthritis can be passed down within a family. Other factors that can contribute to developing knee arthritis include injuries to the knee, torn cartilage, and fractures to the bone around the joint.
Anatomy and Function of the Knee
The three bones that comprise the knee joint are the femur (thigh bone), the tibia (shin bone) and the patella (knee cap).
The knee may be described as a modified hinge joint, similar to the hinge on a door. However the knee not only bends back and forth like a hinge, it has a complex rotational component that occur with flexion and extension of the knee.
The knee is a major weight-bearing joint that is held together by muscles, ligaments, and other important soft tissue.
Cartilage is the material inside the joint that provides shock absorption to the knee during weight-bearing activities such as walking or stair climbing.
Osteoarthritis of the Knee
Arthritis in the knee joint occurs as a result of degeneration of the cartilage in our knee. Osteoarthritis is commonly referred to as “wear and tear” arthritis or degenerative arthritis, and is the most common cause for total knee replacement surgery.
Due to osteoarthritis, the cartilage in the knee breaks down over time and the result is a severely damaged joint surface with bone rubbing on bone. This process may occur as a result of previous trauma to the joint, ligament instability, or abnormal stresses to the joint.
Rheumatoid arthritis is an inflammatory process that results in erosion of the articular cartilage and subsequent damage to the knee joint surface.
What Is Osteoarthritis?
Osteoarthritis, or OA, refers to the breakdown, or degeneration, of cartilage and fluid that cushions and lubricates the bones in your joints.
The degeneration allows your bones to rub together, resulting in pain and further wear and tear. Osteoarthritis is a chronic progressive condition—which means that it gets worse over time.
Osteoarthritis can occur in any joint, but osteoarthritis of the knee is the most common type.
Symptoms of Knee Osteoarthritis
- Look for these common signs and symptoms:
- Pain with activities
- Limited range of motion
- Stiffness of the joint
- Swelling of the joint
- Tenderness of the knee
- A feeling the knee may “give out“
- Deformity of the joint (knock-knees or bow-legs)
Causes of Knee Osteoarthritis
Knee osteoarthritis usually develops slowly and gets progressively worse over time. It’s commonly observed when people are middle-aged and older. But you can develop it at any age, following a joint injury or another disorder.
- There are certain factors that increase your risk of developing knee osteoarthritis:
- Age. The older you get, the higher your risk
- Weight. Increased body weight increases your risk. Every kilogram you gain puts 4 more kilograms of stress on your knees during activities like climbing stairs and getting up from a ground level activity.
- Injury or overuse. Athletes and people with active jobs are at higher risk, esp if an injury to Meniscus, ligament or cartilage is not corrected on time with rest or minor procedures like an arthroscopy.
- Genetics. Recent research suggests that knee osteoarthritis is partially caused by your genes
- Muscle weakness. Weakness in the muscles surrounding the knee increases your risk
- Other diseases. Rheumatoid arthritis, hemochromatosis (having too much iron), and acromegaly (excessive growth hormone) increase your risk
Getting Diagnosed with Knee Osteoarthritis
Do you think you have knee osteoarthritis? Don’t wait. It’s very important that you see a doctor, get a proper diagnosis, and start treatment right away.
The sooner you start treatment, the easier knee osteoarthritis is to control and the less damage it can cause. We have to understand that Osteoarthritis is a progressive disorder. We have methods to prevent the progression of the problem. But we can do very little once it has progressed. If minor injuries to structures inside your knee like the meniscus or ligament are corrected on time you can prevent the occurance, or delay the progression, of a cartilage damage and degeneration.
How is Knee Osteoarthritis diagnosed?
There are usually 4 steps to making a diagnosis of osteoarthritis:
- Medical history. This is your doctor’s best tool to diagnose osteoarthritis. Use the tips below to talk about your symptoms, family history, and past medical conditions
- Physical exam. Your doctor will look for typical signs of osteoarthritis, such as swelling, tenderness, and loss of motion
- Joint fluid sample. After applying a local anesthetic, your doctor will take a small amount of fluid from your knee joint. Lab test on this fluid can help confirm osteoarthritis and rule out other conditions
- X-rays or MRIs. These images can show damage inside the joint. Your doctor will be looking for the deterioration of cartilage that is typical of osteoarthritis
Radiological Grading Of Osteoarthritis
Talking to your doctor
The more you tell your doctor about your knee pain and how it affects you, the more effective your osteoarthritis treatment will be.
- When talking to your doctor, follow the tips below. It may help to write your thoughts down and bring them to your appointment.
- Describe your knee pain in detail. Are there areas that hurt more than others? At certain times of the day? Approximate duration of the problem. How long has it been affecting your day-to-day activities.
- Discuss the effects on your lifestyle. What activities (such as working, exercising, gardening, and/or golfing) cause you pain?
- Tell your doctor about lifestyle changes you’ve tried and their results.
- Mention any medications or treatments you have used for pain relief. What were the results? Were there any side effects like gastritis or nausea with any particular medication?
- Make sure you talk over the treatment plan your doctor recommends. Following the treatment plan is important—ask for it in writing and bring up any concerns you have.
Knee Osteoarthritis treatment options
- Treatment of Knee Osteoarthritis should be stepwise. It should begin with the most basic steps and progress to the more invasive, possibly including surgery. Not all treatments are appropriate for every patient, and you should have a discussion with your doctor to determine which treatments are appropriate for your particular situation. The range of options includes:
- Weight Loss
Probably one of the most important, yet least commonly performed treatments as it is not easy with a joint causing pain. The less weight the joint has to carry, the less painful activities will be. Medications are available for this, but their effect is variable, there are potential side effects and the weight may be gained back once you stop the medication. Bariatric surgery I advice my patients
- Activity Modification
Limiting certain activities may be necessary, and learning new exercise methods may be helpful.
- Walking Aids
Use of a cane or a single crutch is the hand opposite the affected knee will help decrease the demand placed on the arthritic joint.
- Physical Therapy
Strengthening of the muscles around the knee joint may help decrease the burden on the knee. Preventing atrophy of the muscles is an important part of maintaining functional use of the knee.
- Anti-Inflammatory Medications
Anti-inflammatory pain medications (NSAIDs) are prescription and nonprescription drugs that help treat pain and inflammation.
- Cortisone Injections
Cortisone injections may help decrease inflammation and reduce pain within a joint.
VIscosupplementation may be effective against pain in some patients with knee arthritis and may delay the need for knee replacement surgery. Synvisc One (Genzyme) or Duralane (Smith & Nephew) are the commonly used injections worldwide.
- Knee Arthroscopy
Exactly how effective knee arthroscopy is for treatment of arthritis is debatable. For some specific symptoms, it may be helpful.
- High Tibial Osteotomy
While most patients are not good candidates for this alternative to knee replacement, it can be effective for young patients with limited arthritis.
- Knee Replacement Surgery
In this procedure, the cartilage is removed and a metal & plastic implant is placed in the knee.
- Partial Knee Replacement
Also called a unicompartmental knee replacement, this is replacement of one part of the knee. It is a surgical option for the treatment of limited knee arthritis.
- Weight Loss